EP0472248B1

EP0472248B1 - Scroll-type compressor

Info

Publication number: EP0472248B1
Application number: EP91250159A
Authority: EP
Inventors: Yoshiyasu C/O Mitsubishi Jukogyo K.K. Ito; Takayuki c/o Mitsubishi Jukogyo K.K. Ito
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 1990-08-21
Filing date: 1991-06-14
Publication date: 1996-09-18
Anticipated expiration: 2011-06-14
Also published as: KR950013021B1; AU7600091A; CN1059190A; JPH04103893A; EP0472248A1; KR920004730A; CA2041004C; DE69122195T2; US5141422A; CN1032385C; DE69122195D1; AU633208B2

Description

The present invention relates to a scroll-type compressor with the features discloses in the first part of claim 1.
Such a compressor is known from EP-A-39 622. Before showing the invention the general disadvantages of the prior art should be explained by the way of a conventional scroll-type gas compressor.
In Fig. 2, a housing 1 consists of a case body 2, a front case 4 fitted securely to the case body 2 with bolts not shown, and a front cover 6 fitted securely to the front case 4 with a bolt 5. A ring-shaped protruding portion 4a of the front case 4 is engaged with an opening end of the case body 2. A rotary shaft 7 penetrates through the front cover 6, and is supported rotatably by the housing 1 through a bearing 8 interposed between the front cover 6 and the rotary shaft 7 and a bearing 9 interposed between a boss 7a of the rotary shaft 7 and the front case 4.
A stationary scroll 10 and a revolving scroll 14 are installed inside the housing 1.
The stationary scroll 10 is provided with an end plate 11 and a spiral wrap 12 which is set up on the inside surface thereof, and the outer circumferential surface of the end plate 11 is made to come into close contact with the inner circumferential surface of the case body 2 and securely fitted hermetically thereto with a bolt 13. With this, a discharge cavity 31 is defined on the outside of the end plate 11 and a suction chamber 32 is defined inside thereof.
The revolving scroll 14 is provided with an end plate 15 and a spiral wrap 16 which is set up on the inner surface thereof, and the spiral wrap 16 has a substantially identical configuration as the spiral wrap 12 mentioned above.
The revolving scroll 14 and the stationary scroll 10 are eccentric from each other by the radius of revolution and are engaged with each other while shifting the angle by 180° as shown in the figure. Chip seals 17 which are embedded in the point face of the spiral wrap 12 come in close contact with the inner surface of the end plate 15, and chip seals 18 which are embedded in the point face of the spiral wrap 16 come in close contact with the inner surface of the end plate 11. Side surfaces of the spiral wraps 12 and 16 are in linear contact with each other at several locations. In such a manner, a plurality of tightly closed small chambers 19a and 19b forming almost a point symmetry with respect to the center of the spiral are defined.
A bushing 21 is fitted rotatably inside a cylindrical boss 20 which is protruded at the central part of the outer surface of the end plate 15 through a rotary bearing 23. An eccentric pin 25 protruded at the inner end of the rotary shaft 7 is engaged rotatably with an eccentric hole 24 which is bored in the bushing 21. Further, a balance weight 27 is fixed to the bushing 21.
A rotation check mechanism 26 which also serves as a thrust receiving member is interposed between the outer circumferential edge of the outer surface of the end plate 15 and the end surface of the ring-shaped protruding portion 4a of the front case 4.
A sub-balance weight 32 is fitted securely to a boss 7a of the rotary shaft 7.
A suction chamber 35 and a discharge chamber 34 are formed in the case body 2, in which the suction chamber 35 communicates with the suction chamber 32 through a suction port 37 which is bored at a location opposing to the outer circumferences of spiral wraps 12 and 16, and the discharge chamber 34 communicates with the discharge cavity 31 through a through hole 36.
Then, when the rotary shaft 7 is rotated, the revolving scroll 14 is driven through a revolution drive mechanism consisting of the eccentric pin 25, the bushing 21, the rotary bearing 23, the boss 20 and the like. Further, the revolving scroll 14 performs revolution in solar motion while being checked to rotate on its axis by means of the rotation check mechanism 26.
The linear contact portion between spiral wraps 12 and 16 moves gradually toward the center of the spiral with the revolution in solar motion of the revolving scroll 14. As a result, the tightly closed small chambers 19a and 19b move toward the center of the spiral while decreasing the volumes thereof.
Then, a gas is suctioned into the suction chamber 32 through the suction chamber 35 and the suction port 37, and taken into the tightly closed small chambers 19a and 19b from the opening portions at outer terminals of spiral wraps 12 and 16, thus reaching a central chamber 22 while being compressed. The gas passes through a discharge port 29 which is bored on the end plate 11 of the stationary scroll 10 is discharged into the discharge cavity 31 by pushing open a discharge valve 30, and flows out through the through hole 36 and the discharge chamber 34.
In a conventional scroll-type compressor mentioned above, respective sliding parts are cooled and lubricated by lubricating oil contained in a suctioned gas. However, since the suctioned gas enters into the suction chamber 32 through the suction port 37 disposed so as to oppose to the outer circumferences of the spiral wraps 12 and 16 and is taken into the tightly closed small chambers 19a and 19b through the opening at the outer terminal of the spiral wrap 16, there has been such a problem that lubrication and cooling of the rotation check mechanism 26, bushing 21, the rotary bearing 23, the eccentric hole 24, the eccentric pin 25 and the like which form the revolution drive mechanism of the revolving scroll 14 are liable to be insufficient.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the present invention which has been made in view of above-mentioned points to provide a scroll-type compressor in which above-mentioned problems have been solved.
Essential points of the present invention exist in a scroll-type compressor in which a ring-shaped protruding portion of a front case is fitted into an opening end of a case body so as to construct a housing, a stationary scroll and a revolving scroll which are engaged with each other are disposed in the housing, the stationary scroll is fixed to the housing and a thrust receiving member and a rotation check mechanism are interposed between the revolving scroll and an end face of the ring-shaped protruding portion of the front case, and the revolving scroll is made to revolve in solar motion by a rotary shaft supported on the front case through a bearing through a revolution drive mechanism while checking rotation on its axis of the revolving scroll by means of the rotation check mechanism, whereby a gas suction port is opened at a location of the case body where the ring-shaped protruding portion is engaged, and at the same time, at least one and more draught holes including a through hole which penetrates inside opposing to the suction port are provided on the ring-shaped protruding portion.
Above-mentioned construction being provided in the present invention, the operation is such that a gas enters into the housing through the suction port and is sent to the revolution drive mechanism, the bearing, the thrust receiving member, the rotation check mechanism and the like through the through hole and cools and lubricates them at the same time.
As it is apparent from the explanation described above, according to the present invention, since a gas suction port is opened at a location where the ring-shaped protruding portion of the case body is fitted and at least one and more draught holes including a through hole which penetrates inside opposing to the suction port are also provided on the ring-shaped protruding portion, the gas enters into the housing through the suction port and is sent to the revolution drive mechanism, the bearing, the thrust receiving member, the rotation check mechanism and the like through the through hole. Thus, it is possible to improve cooling and lubrication and also to improve the reliability thereof

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention; and
Fig. 2 is a longitudinal sectional view showing a conventional scroll-type compressor.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Fig. 1 shows an embodiment of the present invention.
A fitting block 33 is securely fitted to an outer circumference of a case body 2 with bolts not shown. A discharge chamber 34 and a suction chamber 35 are formed by the case body 2 and the fitting block 33, and the suction chamber 35 extends toward a front case 4 along an axial direction.
A suction port 37 is bored at a location where a ring-shaped protruding portion 4a of the front case 4 is engaged, and the suction chamber 35 communicates with the inside of a housing 1 through the suction port 37. Further, the discharge chamber 34 communicates with a discharge cavity 31 through a through hole 36. A through hole 38 which penetrates to the inside opposing to the suction port 37 is bored on the ring-shaped protruding portion 4a of the front case 4. It is possible to bore a draught hole 39 at the ring-shaped protruding portion 4a other than the through hole 38, and these through hole 38 and draught hole 39 may be formed at the same time as casting draught holes at the time of casting the front case 4.
The suctioned gas enters into the housing 1 through a suction gas pipe not shown, a suction fitting installed on the fitting block 33, the suction chamber 35 and the suction port 37, and a part thereof enters inside through the through hole 38 and is supplied to the bearing 9, the rotary bearing 23, the sliding surface between the eccentric hole 24 and the eccentric pin 25 and the like so as to cool and also lubricate them at the same time.

Claims

A scroll-type compressor wherein a ring-shaped protruding portion (4a) of a front case (4) is fitted into an opening end of a case body (2) so as to constitute a housing (1), a stationary scroll (10) and a revolving scroll (14) engageable with each other are disposed in said housing, said stationary scroll being fixed to said housing, and a thrust receiving member and a rotation check mechanism (26) are interposed between said revolving scroll and an end surface of said ring-shaped protruding portion of said front case, said revolving scroll being caused to make solar motion by a rotary shaft (7) supported in said front case through a bearing (9) by a revolution drive mechanism while checking the rotation of said revolving scroll on the axis thereof by said rotation check mechanism so that suction gas in a first suction chamber (35) formed on said case body can enter into a second suction chamber (32) of both said scrolls, said second section chamber communicating with said first suction chamber, and is compressed by both said scrolls, and then the suction gas thus compressed is discharged from a discharge port (29), characterized in that a fitting block (33) is provided at an outer circumference of said case body, said fitting block forming said first suction chamber (35) extending toward said front case along the axial direction and a discharge chamber (34) in communication with said discharge port(29), a suction port (37) communicating with said first suction chamber is opened in the position of said case body where said ring-shaped protruding portion is engaged, more than at least a draught hole (39) are formed in said ring-shaped protruding portion, including a through hole (38) facing said suction port and opening to said thrust receiving member and rotation check mechanism whereby said suction gas in said first suction chamber is caused to enter into said housing (1) through said suction port (37) and part of said suction gas is supplied to said various mechanisms through said through hole (38), thereby cooling and lubricating said various mechanisms.
A scroll-type compressor according to Claim (1), characterized in that a plurality of draught holes (39) including said through hole (38) are provided on the outer circumference of said ring-shaped protruding portion.
A scroll-type compressor according to Claim (1), characterized in that said through hole (38) and draught holes (39) are formed as casting draught holes at the time of casting said front case.